1. Field of the Invention
The present invention relates to automatic tracking lighting equipment, lighting controller and tracking apparatus, which can automatically track a performer or another object in a space and floodlight it in a site such as a banquet hall, a hall or a stage.
2. Description of the Prior Art
Conventionally, as automatic tracking lighting equipment for automatically tracking a moving target to be lighted such as a person and floodlighting it, for example, Japanese Patent Laid-Open Publication No. SHO 64-33803 discloses one constituted by making the person who is the target to be lighted carry a transmitter of a supersonic wave or a radio wave, providing about twenty receiver sensors on, for example, a ceiling surface of a lighting space having an area of 15 m.times.7.5 m, specifying the transmitter, i.e., the position of the person carrying the transmitter from a reception signal from the receiver sensor and making the lighting direction of a lighting fixture to automatically track the person.
In the automatic tracking lighting equipment having the above construction, in order to correctly specify the position of the transmitter, it has been required to provide a number of receivers on the ceiling surface of the lighting space and clarify a positional relation between the receivers in the lighting space, leading to the problem that an inferior workability results.
By the way, as is commonly known, the lighting controller is to control the direction of a lighting fixture for floodlighting a person or another object moving on a stage and making the lighting position track the position of the person who is the target to be lighted with the movement of the person.
Among the conventional lighting controllers, there is a lighting controller having a constitution in which an operator is located in the vicinity of a space to be lighted (i.e., located in a position where the operator can get the direct view of at least the lighting position), operates the lighting with a remote controller or the like by getting the direct view of the space desired to be lighted and continues operating so that the target lighting position and the lighting position of the lighting fixture coincide with each other.
There is another lighting controller having a constitution in which a camera is fixed to the light body section of the lighting fixture so that the lighting direction of the lighting fixture and the image pickup direction of the camera are arranged in parallel to each other, and the operator continues operating so that the target lighting position and the lighting position of the lighting fixture coincide with each other not by getting the direct view of the space desired to be lighted but by viewing an image picked up by the camera by means of a touch panel or the like provided at the display device that is displaying the image.
There is a further lighting controller having a constitution in which a camera of which image pickup direction is fixed is placed in the vicinity of a lighting fixture, and when an operator inputs a target lighting position while viewing the image picked up by the camera, the lighting direction is moved from the current lighting position to a designated target lighting position.
However, in the lighting controller operated by a remote controller among the aforementioned lighting controllers, the operator must be located in the vicinity of the space desired to be lighted and the operator is required to continue operating while viewing the lighting position until the lighting position reaches the target lighting position. This arrangement has the problem that the operator is required to have a skill to a certain extent and labor and burden are imposed on the operator.
In the lighting controller having the constitution in which the camera is fixed to the light body section of the lighting fixture so that the lighting direction of the lighting fixture and the image pickup direction of the camera are arranged in parallel to each other, and the lighting direction is controlled based on the image picked up by the camera, the operator is not required to be located in the vicinity of the space desired to be lighted, however, the operator is required to continue operating until the lighting position reaches the target lighting position similarly to the above case. This arrangement has the problem that labor and burden are imposed on the operator.
In the lighting controller which controls the lighting direction by the image of the camera of which image pickup direction is fixed, the operator is not required to continue operating until the lighting position reaches the target lighting position once the target lighting position is inputted, however, the mounting positions of the spotlight, camera and so forth are required to be inputted before executing the control. Therefore, the mounting positions must be measured, and this causes the problem that a considerable labor is required for the initial setting.
By the way, in recent years, a tracking apparatus for tracking an object to be tracked is used for the uses of automatically picking up the image of a bride or another object by means of a TV camera and automatically floodlighting the object to be tracked according to the movement of the object in a banquet hall such as a wedding ceremony hall and a hotel. Tracking apparatuses of this kind have been roughly classified into two types of one which tracks an unspecified object to be tracked and the other one of which object to be tracked is predetermined.
The former is to preparatorily store the characteristics (e.g., color and shape) of the object to be tracked displayed on a screen which displays an image picked up by an image pickup means and detect a position in which the highest similarity to the aforementioned characteristics is achieved is detected from the images inputted successively. As a concrete method of this type, there is so-called the template matching. The template matching is to store image data of a region including an object to be tracked as a template, sort the successively inputted images into blocks having the same size as that of the template, calculate every pixel the absolute value of a difference between the template and each block, accumulate the absolute values and adopt the position of the block having the minimum cumulative value as the position of the object to be tracked.
The latter is to detect the position of an object to be tracked by detecting the marker of an infrared light transmitter, a color chart or a reflection tape etc. attached to the object to be tracked by using position detecting sensors, or by extracting them by so-called the binarizing process.
For example, Japanese Patent Laid-Open Publication No. HEI 6-260002 discloses a constitution which detects the position of an object to be tracked by receiving the infrared light from an infrared light transmitter carried with the object to be tracked by light receiving element of the position detecting sensor mounted to the body of the spotlight, and control the lighting derection of the spotlight. Further, Japanese Patent Publication No. HEI 5 -46041 discloses a constitution which detects the position of an object to be tracked, after attaching a reflection marker such as reflection tape or the like to the object, by extracting high luminance points by binarizing the image from pickup means.
According to the prior art tracking apparatus utilizing the template matching, the difference between the values of pixels located at the relatively same coordinates of the template and the block is taken. Therefore, when the shape of the object to be tracked changes (e.g., when the object to be tracked is a human being), the cumulative value of the absolute values of the difference in the correct position disadvantageously increases, and this has sometimes led to a failure in tracking the object to be tracked. Furthermore, there has been the problem that a degraded tracking accuracy has resulted in an environment where a number of objects having a shape similar to that of the object to be tracked exist.
In order to solve these problems of template matching, a method for extracting color information of the object to be tracked and having, for example, a characteristic value as a histogram has been proposed. This method has the characteristic that the histogram does not depend on the shape, the characteristic that the color information has a relative tolerance to a change in lighting and so forth. However, the color information changes when the distance and angle between the object to be tracked and the light changes in the course of tracking, and therefore, the stored color information cannot be extracted, possibly leading to a difficulty in tracking.
On the other hand, the method of tracking by detecting the position of the marker has the characteristic that an output power can be increased when the infrared light transmitter is used as a marker because the infrared light is invisible to the human being and tracking can be stably executed when the infrared light can be stably received. However, there has been the problem that the marker is sometimes made invisible by the object to be tracked itself or another object, and a number of markers (infrared light transmitters) must be attached to the object to be tracked in order to prevent the occurrence of it. Furthermore, depending on the environment of use, it is sometimes the case where a light source having an infrared component such as distance measuring equipment or a halogen lamp of a camera exists other than the infrared light transmitter, when the infrared light from other than the infrared light transmitter is disadvantageously tracked, causing a failure in tracking the object to be tracked.
Also, when a reflection marker such as reflection tape or the like is employed, in case there exist a plurality of high luminance points in the lighting rigion by existence of another reflective object, the possibility of wrong recognition of the object to be tracked become higher, by using of the method which specifies the position of the object only by the binarizing data of luminance, and it causes lack of utility.
The present invention has been developed in view of the aforementioned problems and has an object to provide automatic tracking lighting equipment of which workability is improved.
Further, the present invention has been developed for improving the aforementioned problems and has another object to provide a lighting controller capable of fixing the target lighting position while viewing the lighting position on a display device without requiring the operator to be located in the vicinity of the lighting position and capable of moving the lighting position into the target lighting position by designating once the target lighting position, thereby lightening the burden on the operator, obviating the need for inputting the mounting positions of the lighting fixture, camera and so forth and requiring no substantial labor for the initial setting.
Furthermore, the present invention has been developed for the aforementioned reasons and has further object to provide a tracking apparatus capable of surely tracking the object to be tracked with high accuracy.